Comment by blacklion

Not YET, but there are no any promises too.

New API like secretstream includes algo into API names, so, I hope, it is "stable forever", but it is rather new feature.

Basic APIs like "crypto_secretbox" are "black boxes" and there are no any guarantees spelled out. Algorithms are mentioned in documentation, though.

What will do libsodium if used algorithm will be broken? I don't know.